linux-stable/arch/powerpc/include/asm/sstep.h
Naveen N. Rao 0566fa760d powerpc/kprobes: Roll IS_RFI() macro into IS_RFID()
In kprobes and xmon, we should exclude both 32-bit and 64-bit variants
of mtmsr and rfi instructions from being stepped. Have IS_RFID() also
detect a rfi instruction similar to IS_MTMSRD().

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eee32e1b75dae85d471c89b4c0a123ad4b0aabf8.1621416666.git.naveen.n.rao@linux.vnet.ibm.com
2021-06-25 14:47:18 +10:00

181 lines
4.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM
*/
#include <asm/inst.h>
struct pt_regs;
/*
* We don't allow single-stepping an mtmsrd that would clear
* MSR_RI, since that would make the exception unrecoverable.
* Since we need to single-step to proceed from a breakpoint,
* we don't allow putting a breakpoint on an mtmsrd instruction.
* Similarly we don't allow breakpoints on rfid instructions.
* These macros tell us if an instruction is a mtmsrd or rfid.
* Note that these return true for both mtmsr/rfi (32-bit)
* and mtmsrd/rfid (64-bit).
*/
#define IS_MTMSRD(instr) ((ppc_inst_val(instr) & 0xfc0007be) == 0x7c000124)
#define IS_RFID(instr) ((ppc_inst_val(instr) & 0xfc0007be) == 0x4c000024)
enum instruction_type {
COMPUTE, /* arith/logical/CR op, etc. */
LOAD, /* load and store types need to be contiguous */
LOAD_MULTI,
LOAD_FP,
LOAD_VMX,
LOAD_VSX,
STORE,
STORE_MULTI,
STORE_FP,
STORE_VMX,
STORE_VSX,
LARX,
STCX,
BRANCH,
MFSPR,
MTSPR,
CACHEOP,
BARRIER,
SYSCALL,
SYSCALL_VECTORED_0,
MFMSR,
MTMSR,
RFI,
INTERRUPT,
UNKNOWN
};
#define INSTR_TYPE_MASK 0x1f
#define OP_IS_LOAD(type) ((LOAD <= (type) && (type) <= LOAD_VSX) || (type) == LARX)
#define OP_IS_STORE(type) ((STORE <= (type) && (type) <= STORE_VSX) || (type) == STCX)
#define OP_IS_LOAD_STORE(type) (LOAD <= (type) && (type) <= STCX)
/* Compute flags, ORed in with type */
#define SETREG 0x20
#define SETCC 0x40
#define SETXER 0x80
/* Branch flags, ORed in with type */
#define SETLK 0x20
#define BRTAKEN 0x40
#define DECCTR 0x80
/* Load/store flags, ORed in with type */
#define SIGNEXT 0x20
#define UPDATE 0x40 /* matches bit in opcode 31 instructions */
#define BYTEREV 0x80
#define FPCONV 0x100
/* Barrier type field, ORed in with type */
#define BARRIER_MASK 0xe0
#define BARRIER_SYNC 0x00
#define BARRIER_ISYNC 0x20
#define BARRIER_EIEIO 0x40
#define BARRIER_LWSYNC 0x60
#define BARRIER_PTESYNC 0x80
/* Cacheop values, ORed in with type */
#define CACHEOP_MASK 0x700
#define DCBST 0
#define DCBF 0x100
#define DCBTST 0x200
#define DCBT 0x300
#define ICBI 0x400
#define DCBZ 0x500
/* VSX flags values */
#define VSX_FPCONV 1 /* do floating point SP/DP conversion */
#define VSX_SPLAT 2 /* store loaded value into all elements */
#define VSX_LDLEFT 4 /* load VSX register from left */
#define VSX_CHECK_VEC 8 /* check MSR_VEC not MSR_VSX for reg >= 32 */
/* Prefixed flag, ORed in with type */
#define PREFIXED 0x800
/* Size field in type word */
#define SIZE(n) ((n) << 12)
#define GETSIZE(w) ((w) >> 12)
#define GETTYPE(t) ((t) & INSTR_TYPE_MASK)
#define GETLENGTH(t) (((t) & PREFIXED) ? 8 : 4)
#define MKOP(t, f, s) ((t) | (f) | SIZE(s))
/* Prefix instruction operands */
#define GET_PREFIX_RA(i) (((i) >> 16) & 0x1f)
#define GET_PREFIX_R(i) ((i) & (1ul << 20))
extern s32 patch__exec_instr;
struct instruction_op {
int type;
int reg;
unsigned long val;
/* For LOAD/STORE/LARX/STCX */
unsigned long ea;
int update_reg;
/* For MFSPR */
int spr;
u32 ccval;
u32 xerval;
u8 element_size; /* for VSX/VMX loads/stores */
u8 vsx_flags;
};
union vsx_reg {
u8 b[16];
u16 h[8];
u32 w[4];
unsigned long d[2];
float fp[4];
double dp[2];
__vector128 v;
};
/*
* Decode an instruction, and return information about it in *op
* without changing *regs.
*
* Return value is 1 if the instruction can be emulated just by
* updating *regs with the information in *op, -1 if we need the
* GPRs but *regs doesn't contain the full register set, or 0
* otherwise.
*/
extern int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
struct ppc_inst instr);
/*
* Emulate an instruction that can be executed just by updating
* fields in *regs.
*/
void emulate_update_regs(struct pt_regs *reg, struct instruction_op *op);
/*
* Emulate instructions that cause a transfer of control,
* arithmetic/logical instructions, loads and stores,
* cache operations and barriers.
*
* Returns 1 if the instruction was emulated successfully,
* 0 if it could not be emulated, or -1 for an instruction that
* should not be emulated (rfid, mtmsrd clearing MSR_RI, etc.).
*/
extern int emulate_step(struct pt_regs *regs, struct ppc_inst instr);
/*
* Emulate a load or store instruction by reading/writing the
* memory of the current process. FP/VMX/VSX registers are assumed
* to hold live values if the appropriate enable bit in regs->msr is
* set; otherwise this will use the saved values in the thread struct
* for user-mode accesses.
*/
extern int emulate_loadstore(struct pt_regs *regs, struct instruction_op *op);
extern void emulate_vsx_load(struct instruction_op *op, union vsx_reg *reg,
const void *mem, bool cross_endian);
extern void emulate_vsx_store(struct instruction_op *op,
const union vsx_reg *reg, void *mem,
bool cross_endian);
extern int emulate_dcbz(unsigned long ea, struct pt_regs *regs);